The roller tappet is an important part of the automobile engines using high-pressure fuel pump system, and is mounted between the driving cam and the tappet to transform the rotational motion of the driving cam into the linear reciprocating motion of the tappet. The main structure of the roller tappet includes a shell, a holder, a roller and a pin.
Currently, the height and the mass of the high-pressure fuel pump roller tappet, available in the market, are both large, and the moving inertial force is huge. Hence, an interference with the structure inside the engine occurs easily, increasing the friction and the wear & tear, reducing the efficiency of the engine. Therefore, the high-pressure fuel pump roller tappet does not comply with the requirements of lightweight engines. Moreover, the connecting manner between the shell and the holder is monotonous. Usually, extruding deformation or a connection through pin is used. During rapid movement, the overall stiffness of the high-pressure fuel pump tappet is poor.